The proposed study will make an examination of the role of the Type A behavior pattern in the etiology of poor mental and physical health in the employment setting. The analysis will be guided by the following broad research questions: 1) Do Type A's select themselves into higher stress occupational situations? 2) Do Type A's perceive higher levels of occupational stressors than Type B's even when they are not in objectively more stressful situations? 3) Do Type A's react more strongly to occupational sources of stress than do Type B's? The project will explore these questions using a database uniquely suited to investigating the interactive role of the Type A behavior pattern, occupational differences, perceptual differences of work stressors, and psychological, behavioral, and physiological reactions to work. The data contain responses from 771 individuals in 26 occupations, chosen on the basis of the degree of variance in objective stressors. Measures include a wide range of perceived work stressors (role overload, role conflict, etc), objective work demands from job analyses and supervisor interviews, physiological indices of reactivity, mental and physical health indicators, and Type A behavior pattern as assessed with the Structured Interview method. Analyses will consist of OLS regressions focusing on occupational comparisons as well as relationships at the individual level of analysis. A structural model containing latent variables will also be tested using partial least squares or analysis of covariance structure methods. The proposed analyses are expected to inform a body of research whose long range objectives concern the selection and design of interventions aimed at reducing the mental and physical health-related risks associated with the Type A behavior pattern.